- Acute abscess of a preexisting preauricular sinus
- Preauricular sinus
- First described by Van Heusinger in 1864
- One of the most common congenital abnormalities of the head and neck region
- Sporadic and inherited occurrence
- Synonym(s): infected preauricular sinus; infected ear pit; infected preauricular pit
- Males and females equally affected
- Preauricular sinus forms during antenatal period and present at birth but can become apparent at an older age.
- No defined incidence of preauricular abscess
- Preauricular sinus incidence in the United States is 0.1–0.9%, 0.9% in England, 1.6–2.5% in Taiwan, and 4–10% in some areas of Africa.
No defined prevalence of preauricular abscess
Etiology and Pathophysiology
- Most commonly: Staphylococcus spp.
- Less commonly: Streptococcus spp.
- Three theories for preauricular sinus formation: defective fusion of the six auricular hillocks resulting in preauricular sinus; remnants of incomplete closure of the dorsal part of the first pharyngeal groove; and isolated ectodermal folding during auricular development
- Abscesses are caused by obstruction of these preauricular sinus openings leading to fluid collection within sinus.
- Autosomal dominant pattern with incomplete penetrance and variable expression
- Rarely associated with branchiootorenal (BOR) syndrome (autosomal dominant disorder)
- Poor hygiene
- Preexisting preauricular sinus
- Epidermal cysts
- Pseudocysts of the auricle
Commonly Associated Conditions
Preauricular sinus is rarely associated with hemifacial microsomia and microtia.
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